## yisrael012332 one year ago Evaluate the following expression using the values given: Find 4x - y - 2z if x = -2, y = 3, and z = -2 HELP HELP HELP

1. yisrael012332

@ganeshie8

2. yisrael012332

@Hero

3. yisrael012332

@HWBUSTER00

4. yisrael012332

@dan815

5. yisrael012332

@dan815

6. yisrael012332

@princeharryyy

7. yisrael012332

@PrinceKel

8. yisrael012332

@Michele_Laino

9. yisrael012332

@Nnesha

10. anonymous

Just substitute the numbers given to you into the equation.

11. anonymous

$4(-2)-(3)-2(-2)$

12. yisrael012332

TY IS -7

13. yisrael012332

ITs##

14. yisrael012332

can you help with another

15. yisrael012332

The radius of a cone-shaped tank is 4 feet less than its height. If the height of the tank is (x - 3) feet, the expression below shows the volume of the tank: 1 over 3π(x - 7)2 (x - 3) What does the factor π (x - 7)2 represent?

16. yisrael012332

u have no clue'

17. yisrael012332

i

18. DanJS

Radius is 4 less than the height... write that as it reads, 'is' means equals r = h - 4

19. DanJS

Height is (x-3) h = x - 3

20. yisrael012332

The total surface area of the tank The area of the curved sides of the tank The area of the circular base of the tank The area of the base of about three such tanks

21. yisrael012332

so would it be the 3ed one

22. DanJS

The volume of a Cone is $V = \frac{ 1 }{ 3 }\pi*r^2*h$

23. princeharryyy

insert in the values and solve

24. DanJS

The radius is measured from the wide base of the cone

25. yisrael012332

oh ok so d

26. DanJS

If the radius is height minus 4 and the height is x - 3 r = h - 4 h = x - 3 sub in h for the radius r = (x-3) - 4 = x - 7

27. DanJS

They want to know what pi*(x-7)^2 represents... in other words now that you have r = x - 7 the question is , what is pi*r^2

28. yisrael012332

you lost me

29. DanJS

ok, the givens in the problem are, r = h -4 (radius is 4 less than height) h = x - 3 (height is x - 3

30. DanJS

you get that part?

31. yisrael012332

yea

32. DanJS

To combine those two, you can take the h = x - 3, and insert that into the radius r = h - 4 = (x-3) - 4 r = x - 7 so the radius is in terms of X now, not the height

33. DanJS

good?

34. yisrael012332

no

35. DanJS

The radius is given in terms of the height of the cone... the height is given in terms of a measurememt X... is is one of those compound functions like.. r [ h(x)] You use the height value in the radius , to get r(x), the radius in terms of the measure X instead of height h

36. yisrael012332

i understand but What does the factor π (x - 7)2 represent

37. yisrael012332

i understand how you solved it but how doo i answer the question

38. DanJS

The volume of a cone is $V = \frac{ 1 }{ 3 }\pi*r^2*h$

39. DanJS

recall, the area of a circle is A = pi*r^2 So the Volume of the cone is, 1/3 * ( area of circle base) * (height)

40. yisrael012332

yea ok

41. DanJS

pi times the radius squared is the area of the base in this instance

42. yisrael012332

so its c

43. yisrael012332

like i said

44. DanJS

$V = \frac{ 1 }{ 3 }\pi*r^2*h = (area ~base)*\frac{ height }{ 3 }$

45. DanJS

i didnt look at the answers

46. yisrael012332

The total surface area of the tank The area of the curved sides of the tank The area of the circular base of the tank The area of the base of about three such tanks

47. yisrael012332

i understand the problem no but i wanted to clarify

48. DanJS

a, right on, yeah C

49. yisrael012332

tytytytytyty so much